Rapid evaluation on pharmacodynamics of Curcumae Rhizoma based on Micro-NIR and benchtop-NIR

Abstract

It's far from enough to describe the blood circulation promoting effect of Curcumae Rhizoma (CR), which is widely grown as a functional vegetable or spice in south and southeast Asian countries, and processed Curcumae Rhizoma (PCR), only by disclosing the content of a couple of relative compounds. In this study, the thrombin inhibitory effect as well as 2,2'-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-picrylhydrazyl (DPPH) free radical scavenging ability of CR/PCR extracts was investigated, and TANGO Fourier transform near-infrared (FT-NIR, Bruker, Germany)-a benchtop instrument allowing the full range NIR wavelength scanning-and handheld-NIR spectrometer (Micro-NIR, NIR-S-G1, InnoSpectra corporation, China) that can be connected to smart phones were used to realize the rapid detection of pharmacodynamic indicators. model was evaluated based on the determination coefficient (R2), root mean square error (RMSE), standard error of test set (SEP) and ratio of performance to deviation (RPD). The results of pharmacodynamics experiment confirmed for the first time that CR has significant inhibitory effect on thrombin, and the modeling results revealed that Micro-NIR had a good prediction on the antioxidant capacity (ABTS and DPPH free radical clearance) with RPD greater than 3, but showed a general predictive performance on thrombin inhibition ability (RPD = 2.434). In contrast, FT-NIR provided a good prediction for all the three indicators, with R² greater than 0.9 and RPD greater than 4.5. Further insights into the capability of the two devices were obtained by analyzing the wavebands selection work. In the full wavelength range, wavebands related to thrombin inhibition were mainly distributed in the combination area which is out of the reach of handheld Micro-NIR, thus resulting in a decrease in the prediction ability. Therefore, compared to the benchtop-NIR, the detection range of the handheld-NIR is the main factor limiting its capability Based on an overall assessment, handheld NIR spectrometer, by greatly expanding the application scenario of NIR technology, is considered as a useful device with a satisfying predictive ability through model construction.

Keywords: Antioxidant; Curcumae Rhizoma; FT-NIR; Micro-NIR; Thrombin inhibition.